package com.itheima.reggie.controller;

import com.itheima.reggie.common.R;
import lombok.extern.slf4j.Slf4j;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Value;
import org.springframework.web.bind.annotation.GetMapping;
import org.springframework.web.bind.annotation.PostMapping;
import org.springframework.web.bind.annotation.RequestMapping;
import org.springframework.web.bind.annotation.RestController;
import org.springframework.web.multipart.MultipartFile;

import javax.servlet.ServletOutputStream;
import javax.servlet.http.HttpServletResponse;
import java.io.File;
import java.io.FileInputStream;
import java.io.IOException;
import java.util.UUID;

/**
 * 文件的上传和下载
 */
@RestController
@RequestMapping("/common")
@Slf4j
public class CommonController {

    @Value("${reggie.path}")
    private String basePath;

    @PostMapping("/upload")
    public R<String> upload(MultipartFile file) {

        try {
            //判断目录是否存在，如果不存在则创建
            File dir = new File(basePath);
            if (!dir.exists()) {
                dir.mkdirs();
            }
            // 获取原始文件名
            String originalFilename = file.getOriginalFilename();
            //获取文件后缀
            String suffix = originalFilename.substring(originalFilename.lastIndexOf("."));
            //使用UUID重新生成文件名，防止文件名称重复造成文件覆盖
            String fileName = UUID.randomUUID().toString() + suffix;
            //file是一个临时文件，需要转存到指定位置，否则本次请求完成后临时文件会删除
            file.transferTo(new File(basePath + fileName));

            return R.success(fileName, "文件上传成功");
        } catch (IOException e) {
            throw new RuntimeException(e);
        }

    }

    @GetMapping("/download")
    public void download(String name, HttpServletResponse response) {
        log.info("name:" + name);

        try {
            // 输入流，通过输入流读取文件内容
            FileInputStream fileInputStream = new FileInputStream(new File(basePath + name));
            // 输出流，通过输出流将文件写回浏览器，在浏览器展示图片
            ServletOutputStream outputStream = response.getOutputStream();
            response.setContentType("image/jpeg");
            int len = 0;
            byte[] bytes = new byte[1024];
            while ((len = fileInputStream.read(bytes)) != -1) {
                outputStream.write(bytes, 0, len);
                outputStream.flush();
            }
            outputStream.close();
            fileInputStream.close();

        } catch (Exception e) {
            e.printStackTrace();
        }
    }
}
